Research On Heat Transfer Coefficient Inversion Method Based On The Third Boundary Condition

Heat transfer coefficient is one of the most important characteristic parameter to describe heat transfer process,but in the process of life and production,due to the complexity of the actual heat transfer structure,heat exchange structure uncertainty,and bad thermal environment,traditional methods greatly reduce the accuracy of theoretical analysis and experiments.The heat transfer counterquestion(IHTP)provides a new idea for solving this kind of problem.At present,the domestic and foreign research on the heat transfer coefficient and its inverse problem has been the rapid development,put forward many valuable algorithm,such as iterative regularization method,conjugate gradient method and particle swarm optimization(PSO)algorithm,etc.However,most papers focus on the numerical simulation stage.As the algorithm does not rely on the actual measurement data,the proposed algorithm is divorced from the actual situation.In this paper,an inversion method of forward heat transfer process based on the third kind of boundary conditions is constructed.The method includes a mathematical model with the actual situation in accordance with good,can a basic consistent with the measured temperature field is the problem of calculating method,and the ability to obtain effective results of inversion algorithm,finally able to verify the heat transfer coefficient by the real data inversion method.In temperature field is problem solving,first of all discussed the current commonly used the principle of heat conduction is problem solving method,including the finite difference method and finite element method,and then discusses the finite element method(FEM)in 2D and 3D model is performance in question.By comparing the advantages and disadvantages of each method and the reasons of balance precision and operation cost,the two-dimensional finite element method was finally selected to solve the positive problem.The idea and characteristics of regularization method are introduced in solving the inverse problem,and the inverse process of the weighted iterative Tikhonov regularization is given.Then,the method of parameter optimization in the process of iterating Tikhonov regularization is presented.The simulation results show that the optimized parameters perform well in the inversion process.Next,this paper briefly introduces the main structure and improved structure of the heat conduction forward generating platform,and then builds a two-dimensional simulation model based on the platform.In simulation experiments,discussed the selection of regularization parameter sensitivity to noise,the influence of boundary conditions(including surface coefficient of heat transfer and fluid temperature)regularly change on the impact of the inversion results,the quantitative inversion algorithm of noise resistance.Finally,noise analysis and processing of measured data are carried out in this paper.The surface heat transfer coefficient is inversed with measured data.The heat transfer coefficient inversion algorithm studied in this paper is validated by using Newton cooling formula.The results show that the algorithm has good noise resistance and the inversion error is within 8%.